REFLECTOR: Ailerons

[Laurence Coen]

David,

The aileron control linkages can't cause or prevent aileron flutter. 
Ailerons that are not properly balanced will cause flutter.  Your ailerons 
must be of a different design than mine.  Mine have a lower leading edge 
that is the counter weight which is a 3/8" steel rod and thus no sharp 
edges.  You have said that you rounded off the leading edge of your aileron 
to prevent the "aileron snatch" that you were experiencing.  My concern is 
that your ailerons are no longer balanced and that could lead to flutter as 
you approach Vne.  I think it would be a good idea to re-check the balance 
just to be sure.

The friction you have noted is normal and in my experience has become less 
with use.  It is also normal that the roll trim doesn't move the ailerons.

Larry Coen
N136LC

--------------------------------------------------
From: "David Ullman" <ullman at robustdecisions.com>
Sent: Monday, December 26, 2011 12:07 PM
To: <reflector at tvbf.org>
Subject: Re: REFLECTOR: Ailerons

> I am still struggling with the ailerons.  Scott has spent much time on the
> phone with me and I appreciate this factory support.  I have torn out the
> push pull cables and rerouted them making the angle to the control horns
> near 90deg and relaxing radius of the cable bend.  I have virtually no 
> slop
> in the system .  The trim system still cant move them and there is still
> more friction than I would like on the stick.  It is much, much less than
> when I started and a flight test will tell if this is good enough(my test
> pilot is on vacation).  Any other ideas are appreciated or comments on
> aileron stiffness.
>
> One problem came out that I haven't fixed is that I have aluminum torque
> tubes on the ailerons.  These came with the kit.  The factory now uses
> steel.  I calculated the difference in stiffness between a .035 steel and
> the .06 aluminum tube and it is a factor of 2.0  Statically, I don't think
> that a pilot could feel the difference in the resulting stiffness.  But, 
> my
> test pilot is worried about flutter.  He has experienced this twice in 
> Reno
> racer development and both had aluminum torque tubes. Should I swap these
> out before it flies again., or can it wait until I take the plane apart 
> for
> painting in a year?
>
> Happy new year to all and I may get to fly in 2012 (I said that last year
> also).
>
> David Ullman
> N-444DX Velocity
> EAA 292 President
> david at davidullman.com
> 541-754-3609
>
> **************
>
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